Abstract

This is the second of two papers which screen the environmental fate of sludge or sludge organic contaminants when applied to agricultural land. A simple screening model has been developed to assess the likelihood of organic contaminants accumulating into the food-chain following the application of sludge onto arable and pasture land. The purpose of this exercise is to highlight those compounds that have the potential to accumulate into plants and animal tissues using data on physico-chemical properties of the compounds of interest. Over 300 organic compounds or groups of compounds which have been identified as potential pollutants in sludge have been screened for their potential to transfer from sludge-amended soils to plants via retention by root surfaces, root uptake and translocation, foliar uptake and animal intake via soil and herbage ingestion. Various organic contaminants have been identified as having a high potential to transfer into the food-chain through plant and animal accumulation. Two priority lists have been produced to include (a) those compounds which are shown as being of sufficient or suspected importance, but for which further sludge concentration data and fate studies would be necessary to check on their status, and (b) those compounds which have been highlighted in the screening processes as having a high potential to accumulate up the food-chain. This screening approach can be adapted to other chemicals as information on new chemicals and their physico-chemical properties becomes available.